Externa RAM

Hello Pavel,

TM4C129 has EPI module to communicate with an external memory (SRAM, SDRAM, PSRAM). The typical use case is spec-ed for SDRAM and there are examples for the same.

For an external SRAM (we have tested Cypress SRAM 8 and 16-bit's), and can help you develop the driver, if you have some code already. You can use pointers as usual.

Regards

Amit

@Amit,

Client of ours has similar need/app. - while away from office may I seek your assistance?  Recall that your/ex Dave W. and I past discussed the fact that not all, "TM4C129 devices" had direct-drive, TFT support. (only the largest devices contained those extra - TFT targeting pins)

Thus - might a similar limitation impact poster's (and our client's) use of TM4C129 - strictly for external SRAM use?  (i.e. do all models of TM4C129 provide similar EPI capability)   I don't travel w/TM4C129 spec - hope is that such knowledge is w/in "Amit's expansive (internal) memory-bank..."

Thank you/regards...

Hello cb1,

All the TM4C129 parts support EPI. However when it comes to LCD, there are only 6 parts which would support an LCD interface in TM4C129.

Regards

Amit

@ Amit,

Thank you - again great response - appreciated.  (note - my keyboard "fell overboard" today!  Spacebar now sticks/skips - my 60 wpm in great jeopardy)

May we assume that the number of address/data/control lines (separate from LCD) are then equal across each/every "flavor" of TM4C129?  (some makers limit EPI/similar off-chip capability - based upon package size & MCU performance level/grade...)

Again thanks & regards...

Hello cb1_mobile,

Yes, all the EPI address/data/control lines (36 of them) are available in both the packages. There is no limitation in terms of performance that is there on any of the 20 parts in TM4C129 series.

Sometimes, I need to be reminded as well by the forum that my familiarity with the TIVA devices may lead to put a half baked answer. :-)

Regards

Amit

Hello Amit,

Again thanks - completely clear now.

Let the record show that any, "half-baked answer" likely followed my, "half-baked question!"  Detail - as always - is demanded by "both sides..."

(as an aside - do hope that you "take to heart" my defense of you as regards what myself/several other (valued others) judge to be vendor abuse - targeting your good nature.  Some rtc application effort is required by the client/user!)

I'm fortunate enough to own a sailboat - it cost many magnitudes beyond a Tiva/Stellaris board/chip.  Yet I never call or pester the shipbuilder for basic marine charts, or weather reports - or what to do when I, "run aground!"  (I have - years past - dug the keel into soft sand - coast guard "broke us free/rescued...")

Point is you help many here - I was always discomforted by the move toward, "booster packs" - and their potential distraction/disruption of this forum's "true MCU focus."  Poster in question did not appear to have known (nor studied) the "basics."  You presented such powerfully/clearly.  To myself/others - that should be "the end!"  A code bombardment followed - time/effort spent there (improperly we believe) surely drains you from your key, much valued, MCU focused, "task at hand."  

Know that many here thank, appreciate, and are greatly assisted by your "MCU-centric" efforts.  I'd like to see you keep your focus - your curiosity - your desire!  Vectoring off into clearly, "application sandbars" was not healthy for my boat - may prove similarly disfunctional to your (proper) MCU efforts here.   (someone had to say this...)

Thank you.

And what about TM4C123? There is register "Device Capabilities 2 (DC2)" which has bit EPI0, that tell me, if EPI module 0 is present. Is it the right way? Which procesors (TM4C123) have this module?

Pavel

Thank you for your answer.

Have a nice day. 

Pavel